Notes Payable - Borrowings (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Due within one year:
Current portion of medium-term notes	$ 7,391,144	$ 6,986,799
Weighted - average rate (as a percent)	1.78%	0.45%
Medium-term notes due in:
Two years	$ 4,057,284
Three years	3,184,014
Four years	2,534,177
Five years	2,705,529
Thereafter	4,194,915
Total due after one year	16,675,919
Total principal net of discounts	24,067,063	$ 22,758,533
Hedging adjustments	(566,406)	(44,762)
Total	$ 23,500,657	22,713,771
Weighted - average rate (as a percent)	1.77%
Total weighted - average rate (as a percent)	1.77%
Two years
Medium-term notes due in:
Weighted - average rate (as a percent)	1.40%
Three years
Medium-term notes due in:
Weighted - average rate (as a percent)	1.59%
Four years
Medium-term notes due in:
Weighted - average rate (as a percent)	1.28%
Five years
Medium-term notes due in:
Weighted - average rate (as a percent)	2.10%
Thereafter
Medium-term notes due in:
Weighted - average rate (as a percent)	2.34%
Discount notes
Due within one year:
Current portion of medium-term notes	$ 867,588	$ 2,167,979
Weighted - average rate (as a percent)	2.07%	0.05%
Short-term debt, average outstanding during the quarter	$ 1,525,565	$ 1,822,714
Weighted - average rate, average outstanding during the quarter (as a percent)	0.67%	0.08%
Medium-term notes
Due within one year:
Current portion of medium-term notes	$ 1,905,291	$ 837,580
Weighted - average rate (as a percent)	2.78%	0.09%
Short-term debt, average outstanding during the quarter	$ 1,166,242	$ 1,956,870
Weighted - average rate, average outstanding during the quarter (as a percent)	1.39%	0.12%
Medium-term notes due in:
Two years		$ 4,179,985
Three years		2,554,906
Four years		2,119,805
Five years		2,810,894
Thereafter		4,106,144
Total due after one year		$ 15,771,734
Weighted - average rate (as a percent)		1.10%
Total weighted - average rate (as a percent)		0.90%
Medium-term notes | Two years
Medium-term notes due in:
Weighted - average rate (as a percent)		0.81%
Medium-term notes | Three years
Medium-term notes due in:
Weighted - average rate (as a percent)		0.87%
Medium-term notes | Four years
Medium-term notes due in:
Weighted - average rate (as a percent)		0.85%
Medium-term notes | Five years
Medium-term notes due in:
Weighted - average rate (as a percent)		1.07%
Medium-term notes | Thereafter
Medium-term notes due in:
Weighted - average rate (as a percent)		1.69%
Current portion of medium-term notes
Due within one year:
Current portion of medium-term notes	$ 4,618,265	$ 3,981,240
Weighted - average rate (as a percent)	1.31%	0.75%